Symptoms related to gastrointestinal tract involvement and low muscularity in systemic sclerosis

Gastrointestinal tract (GIT) involvement is frequently observed in systemic sclerosis (SSc) and may lead to nutritional impairment. The aim of the study was to assess the prevalence of symptoms related to GIT involvement and to analyze the possible association between gastrointestinal symptoms and low muscularity in SSc patients.

Sixty-nine consecutive patients (60 females, median age 53 (IQR 43-63), body mass index (BMI) 23.2 (IQR 20.9-24.6) kg/m²) with diagnosis of SSc admitted to our Scleroderma Unit were enrolled. Clinical status, anthropometric data, and bioelectrical impedance (Inbody 770, USA) analysis-assessed Fat-Free Mass Index (FFMI) were recorded upon enrollment. UCLA questionnaire was used to quantify GIT involvement with seven specific scales.

Mean FFMI was 16.2 kg/m² (IQR 15.2-17.6). The median UCLA total score was 0.53 (IQR 0.19-0.89). FFMI showed a significant negative correlation with UCLA total score (r = -0.29, p = 0.016) and UCLA distention/bloating (r = -0.35, p < 0.01). In 16 patients (23.1%), FFMI was reduced and UCLA distention/bloating was significantly higher (p = 0.039) in SSc patients with lower FFMI [1.75 (IQR 0.75-2.12) vs 0.75 (IQR 0.25-1.75)]. At multiple linear regression model, FFMI showed association with UCLA distention/bloating [beta coefficient - 0.315 (95% CI of beta coefficient: -0.591; -0.039), p = 0.026], BMI [beta coefficient 0.259 (95% CI of beta coefficient: 0.163; 0.355), p = 0.001], and disease duration [beta coefficient - 0.033 (95% CI of beta coefficient: -0.059; -0.007), p = 0.015].

In SSc, low FFMI is associated with symptoms related to GIT involvement, in particular with distension/bloating. Key Points • FFMI is associated with symptoms related to GIT involvement. • Low FFMI is associated with symptoms related to UCLA distention/bloating. • Malnutrition is not associated with symptoms related to GIT involvement.